this morning, an epic disaster on two fronts. we're seeing the extent of the damage for the first time, and we're learning that the death toll in japan could be exponentially higher than initial estimates. in one state alone, they say there could be more than 10,000 dead. christiane amanpour covers it all from the air and from the ground along with our team of reporters caught in the aftershocks. and compounding the natural disaster, a potential nuclear one. partial meltdowns may already be happening at two reactors in japan, and four more are at serious risk this morning. nearly 200,000 people have been evacuated. there are reports that some people are already sick, and now the government is planning to hand out special tablets to protect people, especially children, from cancer.

and just now we're getting word that the prime minister of japan is calling this japan's greatest hardship since world war ii. it's a situation that's changing by the second. as we said, the japanese government now admits that there may be partial meltdown happening at two reactors at one nuclear facility in the quake zone, and they are warning that another explosion similar to yesterday's could be imminent. so far, though, no reports of any massive radiation leak, but the situation does remain unstable. people within a 12-mile radius are being evacuated. and take a look at this. a photo that says just so much. a small child who lives near the reactor being scanned for exposure to radiation. and that wild is probably not the only child who has to go through that experience. >> he is absolutely not. has to be scary and confusing for children there. this is an unprecedented

man-made disaster layered on top of an unprecedented natural disaster. we want to show you some new video we just got this morning. this is the fishing village of miyako just as the tsunami hit on friday. i'm going to pause and let you watch and listen. >> and then here's the other side of it. we have incredible rescue video coming in from japanese tv. as you can see here, firemen carrying an older woman out of the rubble with smoke everywhere. and then here's another image, two people standing on the roof of a completely toppled three-story building. and from a helicopter hovering above a flooded house with people dangling from a wire. and then there's this, an emotional scene of a girl being taken through high water to be reunited with her mother. >> nice to see some happy news this morning. we have the latest numbers for you. now, these numbers, i have to warn you, will almost certainly rise.

the official death toll now, 977. but as we mentioned, officials say as many as 10,000 people may be dead in one state alone. as of right now, it's estimated around 10,000 people are missing, although the official number is much lower than that. and this morning, 49 countries, including the united states, have stepped forward to help japan at this moment of maximum desperation. >> and we're going to begin with our christiane amanpour who is in tokyo's. she's been getting a firsthand look at the worst hit areas. and, christiane, we're really learning just how bad that devastation is. >> absolutely. and as you mentioned, the japanese prime minister has just been on television. he's been giving regular briefings. and lately he's just said that the japanese have managed to rescue some 12,000 people. we're here at the narita airport area, and that is where all the crews and rescue officials from various different countries are landing to go out and help with the effort and believe me, from what we saw firsthand today, the japanese are going to need every

bit of help they can get. helicopters continue to air-lift survivors. police, military, and emergency workers together are trying to rescue victims, old and young. while over 300,000 people are living in shelters uncertain of when or if they can go home. >> translator: the tsunami swept away my car, and my house is burned down by the fire afterwards. my sons must be very worried about me. >> reporter: meanwhile, international aid is streaming into airports to offer assistance. >> we would like to help the people here, and it's just our opportunity to help the people here, and we would like to help them. >> reporter: i got a firsthand glimpse of the devastation. flying overhead you can see that most of japan looks surprisingly untouched by the worst earthquake in this country's history. but as we fly closer to the coast, the devastation becomes painfully clear. the ocean has swallowed most of what stood on this shoreline

leaving behind only a small smattering of houses and patches of debris floating like islands. and above this washout, a giant plume of black smoke billowing from a petrochemical plant that has caught fire. we could see oil seeping into the ocean beside it. despite the huge magnitude of the earthquake, it is clear that most of the damage was caused not by the temblor itself but the tsunami it unleashed. a powerful reminder of the force of nature that has racked this nation. but now an equally pressing concern, the dangerous situation at one of japan's major nuclear installations. at the fukushima nuclear power plant, a second reactor is being filled with seawater to prevent the fuel rods from melting down. still government officials say they are bracing for an explosion there too because of a dangerous buildup of hydrogen gas.

now, the japanese authorities have said that they have doubled the number of defense forces that they're deploying to this rescue effort from 50,000 to 100,000. and alarmingly, the japanese government is saying that perhaps sometime in the next three days, there could be another earthquake of a 7.0 magnitude. back to you. >> that's terrifying to hear. christiane, thank you so much. of course, christiane will have much more from japan on a special edition of "this week" later on this morning. dan? while christiane has been viewing the destruction from the air, our clarissa ward has traveled by land to sendai, which as you know, is the largest city near the epicenter. she joins us now from sendai. clarissa, good morning. i understand you have seen some truly horrific things. >> reporter: good morning, dan. that's right. we were in that devastated port area today. the police have now completely blocked that off because it's getting late here. and they say with such a high risk of further quakes, it is simply impossible for us

to be there at night. the port of this modern city now almost like a war zone. soldiers watching over charred debris. plumes of smoke billowing from a burning refinery. [ sirens ] police and firemen pouring in to assess the enormous damage. this area was completely submerged by that wall of water coming with that force and just completely devastating this area. looking around, it's almost an apocalyptic landscape. you see here cars on top of houses literally. other houses completely crumpled. it's just hard to imagine how anyone possibly could have survived this. moments later a firemn orders people to immediately get out. sirens wail as we dash back to the car. residents of this area had less than a half an hour to get to higher ground.

"when i got home i heard a neighbor shouting a tsunami is coming" this woman said. "when i got out of the house, i saw the tsunami approaching." today, the roads choked with ten-block-long lines for gas now being rationed. countless people living in schools and hospitals. "everything was turned upside down after the tsunami. our house was gone," this man said. "we lost everything." and, you know, even for people who haven't lost their homes, life here is just incredibly challenging at the moment. we saw long lines outside of convenience stores. people saying, you know what? it's been two days. we have no supplies, and we're starting to get anxious. bianna? >> i'll pick it up from here, clarissa, thank you. we're going to turn now to the other front in this disaster, the nuclear one. as we said, the japanese government now says two reactors are in partial meltdown and four more are at risk. they're warning that another explosion similar to the one we saw yesterday could be imminent. they say they're doing everything they can to contain the damage before any radiation is released. but 170,000 people have been

evacuated from those areas around the facilities. now, i want to say the word "meltdown" is being used a lot these days. it's a loaded and scary term. so we want to be absolutely clear about what it actually means. ron claiborne is here with a quick explanation of what exactly happens when a nuclear reactor melts down. ron? >> all right, dan, let's start with a simple graphic of a nuclear reactor. now, normally the uranium core, the potentially dangerous part of the plant is immersed in a coolant. that is usually water. that coolant is constantly being pumped in and out to keep the core cool. when it struck, it went down and the core had nothing to keep it cool so it began heating up, boiling off that water. if that water eventually boils away, it exposes the core and that's when the real trouble starts. once the temperature reaches 5,000 degrees, that's when you begin to have the meltdown. if the unstable uranium is disturbed in any way, it explodes, bursting through the vessel that contains it

releasing dangerous radioactive particles into the air and that is the worst case scenario there that many fear could happen in japan. dan, bianna? >> ron, thank you. we want to drill down on all of this now with two special guests, dr. michio kaku, who is a physicist. good morning to you. also abc news chief health and medical editor, dr. richard besser, thank you for coming in, as well. dr. kaku, we want to start with you. on the issue of the meltdown, is it possible to have a fuel meltdown, to have all the uranium turn into liquid and still have it contained in the vessel, in other words, to not pose a health risk to the people around it? >> the answer is yes. a meltdown is not just one incident. there are degrees of melting. let's say that this, for example, represents the reactor at fukushima. the red here represents the super hot core that has to be continually bathed in water. what happens is, if you have a partial meltdown, water levels drop, and then temperatures rise, and the core begins to melt. but seawater is coming to the rescue. this is unorthodox.

we've never done this before. this is a science experiment in the making. they're literally making it up as they go along. this is seawater being dumped to prevent the full-scale melting. but even if there is full-scale melting, it takes an explosion to then blow the whole thing apart. so a meltdown is in stages. it takes 30 minutes to several hours for a full-scale meltdown. >> and, dr. kaku, as you've mentioned, this is a science experiment in the making. uncharted territory that the japanese are in right now. what should we be paying attention to in the coming hours and days to make sure a crisis has been averted? >> first we expect that this second reactor, unit three, may have another hydrogen steam explosion. so it's like deja vu all over again. another repeat of the first accident. second, if there's a secondary earthquake, that could tip the whole thing over, pipes could break, leaks could take place. and even as you put seawater in, the water could bleed out creating a full-scale meltdown. that's the nightmare scenario. more pipe breaks. >> and we hear nightmare

scenario. we want to turn to our dr. richard besser because we're fortunate enough to have you here. you were in charge of the emergency response at the cdc. and what you're seeing and how the japanese are reacting, evacuating people within a 12-mile radius, is that the proper procedure and are they acting accordingly with how you were trained? >> they're doing the exact same things we would be doing. it's almost like they have a blueprint and they're working off the same playbook. what you want to do is prevent as much radiation exposure as you can so here they're evacuating people here a safe distance away. whether or not there will be further leaks, these people will be away from danger. they'll be monitoring them as they come out to see if they have radiation on them. they can decontaminate them. they'll be protecting workers to make sure they have respiratory equipment so they're not breathing this in within the building and they have protective equipment and they'll be monitoring them, as well. they'll distribute potassium iodide for the population in that area as a very important prevention measure. >> why is that so important, the iodide?

>> you can't prevent all the cancer and all the consequences of radiation exposure, but you can prevent thyroid cancer. thyroid cancer is caused because your thyroid gland in your neck takes up iodine to make thyroid hormone. your body needs that. one of the things released by that is radioactive iodine. if you give people potassium iodide, a simple little pill, your body will take that up and won't incorporate the radiation into the gland. one of the things after chernobyl, you saw massive numbers of cases of thyroid cancer in children. it wasn't so much from that initial exposure. what happened was the radiated -- the radioactive iodine fell on the ground. it contaminated the grass, the cows ate that and it got into the milk. it was really from drinking contaminated milk that you saw this. one of the things you'll see, if there is a big fallout, is that they will tell people not to eat food or drink milk from that area. children and pregnant women are most at risk. >> dr. kaku, we think back to chernobyl and the

concerns that we saw this. should this radius, as far as evacuation be extended in your opinion in japan? >> i think as a precaution it should be extended because the winds don't stop blowing at 12 miles. as you know, the winds can blow 20, 50 miles downwind of that reactor accident. and computer models show that radiation doesn't disperse in a sphere or a circle. it disperses in a plume, a pencil-like plume that then waves with the wind like a lighthouse, and so the radiation is concentrated along that plume. so i think as a precaution people should evacuate even farther. >> very quickly, do you trust what you're hearing from the japanese officials about the steps they're taking to contain the damage at the reactor? >> the japanese nuclear industry is famous for low-balling and underestimating all the disasters and later it turns out scandalously in the newspaper that they knew things were worse than they thought and they didn't reveal it. for example, cesium and iodine are only released in a core meltdown. when you have smoke, you have

fire. but for many, many days they simply refused to admit that there was melting in the core. and yet, there it was. cesium and eye design which are only released if there is melting. >> dr. michio kaku, thank you very much and dr. richard besser. we appreciate both of you coming in this morning. we want to go to one story of a woman who got out. emma gibson, an australian english teacher, who lives in a town not far from the epicenter, and here she is in her own words. >> we stayed outside for awhile because there were so many aftershocks, then the tsunami hit, and we had to move to one of the evacuation zones straightaway. we stayed there overnight and they woke everyone up about 6:30 in the morning and we were all out of the building by 7:00. they were trying to get everyone either onto buses or into their cars. everyone was just sleeping in the stairwells, under the desks, the furniture and things like that. we were all inside. and they basically just told us that they were having concerns

about the nuclear power plant down the road. we were within the radius. and they were just for like safety reasons needed us to get out of town. everyone started running for their cars going out of town. a lot of people were really afraid because some people don't have cars or they were evacuated without access to their cars, and no one knew where to go or what to do and how to get everyone out of town. >> of course, you can imagine there are many stories similar to emma's. meantime, the world has been horrified and mesmerized by the imaging pouring out of japan and this morning we have these remarkable before and after shots that really give you a sense of the magnitude of the disaster. first the sendai airport before and after the tsunami. and that was the tsunami actually hitting the airport. you see that realtime terrifying. unbelievable. next, this town along the northeast overwhelmed by the waves. and finally the farmland in soma, japan, transformed into

vast lagoons after the tsunami thundered through. >> all right. we want to check the rest of the morning's news now with ron claiborne back once again. good morning, again. >> hey, good morning again, dan and bianna. good morning, everyone. we begin with the largest crowd yet of pro-labor protesters in madison, wisconsin. police estimate that between 85,000 and 100,000 people rallied at the state capitol. they're protesting a controversial new law that would strip public workers of most collective bargaining rights. protesters are vowing a political counterattack in the 2012 elections. and the death toll in yesterday's horrific bus crash here in new york city is now 14. the bus was returning from a connecticut casino when it flipped onto its side and was split open when it struck a large sign post. about 20 other passengers were injured. 8 are in critical condition. witnesses say it was traveling at a high speed. a court in cuba has found american contractor alan gross guilty of crimes against the state. gross was sentenced to 15 years in prison for what's called a subver subversive program to bring down

the cuban government. the u.s. condemned that verdict. gross was convicted of bringing satellite equipment to cuba to improve internet access for the country's jewish community. and the afghan government says that four civilians were killed by a roadside bomb. the victims were driving in kandahar province in southern afghanistan on saturday when their vehicle hit the bomb. the taliban recently increased attacks on civilians there. and finally, in bismarck, north dakota, the national guard had to be called in to rescue hundreds of people stranded in a blizzard. about 800 motorists were trapped in vehicles by huge snowstorm in whiteout conditions. two highways were closed by the snow. the weather here has been so nice, i keep forgetting that it's still winter out there. elsewhere. >> it is, ron. thank you. speaking of weather, we want to turn to stephanie roberts from our tampa affiliate, wfts. good morning to you, stephanie. >> good morning. and speaking of winter we are looking at another storm system moving into the northwest part of the country and we'll see heavy rain, mountain snow and gusty winds from seattle to

portland even into northern california. it looks like the worst weather we a will stay north of san francisco. but numerous watches and warnings have been issued already for that part of the country. winds being the big headline. we may see gusts of 60 miles per hour and weak storm system bringing rain and above norma >> dan and bianna? >> thank you, stephanie. coming up, back to japan. the road of ruin. our correspondent touring the destruction caused by the mighty

one/two punch of an earthquake and tsunami. david muir coming up. and the missing americans living in the danger zone, not heard from since the quake hit. how their loved ones back at home cope as facebook and twitter give them hope. ve them hope. ♪ [ male announcer ] here they come. all the new tech products you need. and they're all looking for the same thing. ♪ the one place that makes technology easy. staples. with highly-trained tech experts and expanded tech centers, staples makes finding the right technology just the way you want it. easy. easy to buy. easy to fix. easy to save. staples. that was easy. ♪ [ female announcer ] mini, meet berries.

introducing new kellogg's frosted mini-wheats with a touch of fruit in the middle. helloooooo fruit in the middle. air optix contacts let up to five times more oxygen through the lens for enhanced breathability. air optix. the lens you can survive a long day in. go to airoptix.com for a free one-month trial offer. air optix. the lens you can survive a long day in. heaven comes to earth. rich, creamy, thick dannon greek, the most delicious yogurt heaven on earth! discover dannon greek

♪ ♪ ♪ ♪ ♪ ♪ ♪ [ female announcer ] introducing purina one beyond, a new food for your cat or dog.

well, coming up on "good morning america" how social networking sites like facebook and twitter are helping those in america search for missing loved ones in japan. also, ron is going to take a look at whether the earthquake like they had in japan, if it hit us in the u.s. what would happen. and we have a special version of "your three words" dedicated to the victims in japan following that earthquake and tsunami. stick with us, we'll be right back after the break. [ male announcer ] it's simple physics...

a body at rest tends to stay at rest... while a body in motion tends to stn motion. staying active can actually ease arthritis symptoms. but if you have arths, staying active can be difficult. prescription celebrex can help relieve arthritis pain so your body can stay in motion. because just one 200mg celebrex a day can provide our relief for many with arthritis pain and inflammation. plus, in clinical studies, celebrex is proven to improve daily physical function so moving is er. and celebrex is not a narcotic. when it comes to relieving your arthritis pain, you and your doctor need to balance the benefits with the risks. all prescription nsaids, including celebrex, may increase the chance of heart attack or stroke, which can lead to death. this chance increases if you heart disease or risk factors such as high blood pressure or when nsaids are taken for long perio nsaids, including celebrex, increase the chance of serious skin or allergic reactions or stomach and intestine problems,

such as bleeding ann occur w. patients also taking aspirin and the elderly are at increasesk for stomach bleeding and ulcers. do not take celebrex if you' had an asthma attack, hives, or other allergies to aspirin, nsaids or sulfonamides. get help right away if you have swelling of the face or throat, or trouble breathing. tell your doctor about your medical history and find an arthritis treatment that works for you. ask your doctor about celebrex. and, go to celebrex.com to learn more about how you can move toward relief. celebrex. for a body in motion.

with chili's new $6 lunch break. choose a salad or tasty soup. pair it with a texas toast half sandwich, like our southwestern blt with applewood smoked bacon. served with fries, it's big flavor for just 6 bucks! weekdays at chili's.

but we still may suffer from nasal allergy symptoms. they can hit you year round... indoors or out. achoo! oh to have relief. prescription nasonex is clinically proven to help relieve nasal allergy symptoms... including congestion, runny and itchy nose and sneezing. [ female announcer ] side effects may include headache, viral infection, sore throat, nosebleeds, and coughing. infections of the nose and throat and eye problems, including glaucoma or cataracts may occur. have regular eye exams. slow wound healing may occur, so do not use nasonex until your nose has healed from any sore, surgery or injury. nasonex can increase your risk of getting infections. avoid contact with infections like chicken pox or measles while using nasonex. it does not come in generic form. ask your doctor if nasonex is right for you.

and we once again want to begin this half hour by showing you that dramatic new video of the tsunami hitting the village of miyagi in japan on friday. we're getting our first look at the extent of the disaster there. the prime minister of japan is calling this japan's greatest hardship since world war ii. good morning, america. i'm bianna golodryga. >> and i'm dan harris. this is sunday, march 13th. and every time we see new pictures like this, it is truly hard to absorb. this natural disaster has now spawned a potential nuclear one. japanese officials say there have been partial meltdowns at a pair of nuclear reactors that were damaged in the quake and then in the tsunami afterwards. four others are at serious risk this morning. they're warning that another explosion like the one we saw yesterday could be imminent. so far there are no reports of any massive radiation leaks. but 170,000 people have been

evacuated from the areas around those nuclear facilities. >> and as far as getting the latest numbers, right now the official death toll is at 977 but an official in one state says there could be as many as 10,000 dead. it's estimated around 10,000 are missing, although the official number is much lower, just 739. and 49 countries, including the u.s., have stepped forward to help japan. >> this morning the race is on to rescue the people who survived this disaster. so we're going to start with weekend "world news" anchor david muir, who is in hitachi, japan. david, good morning to you. >> reporter: dan, good morning to you. and as those rescues continue there's also another major need emerging, the humanitarian one. as we travel through rural japan, we can't help but notice the need for water. more than 1 million homes without water. food and gas is drying up. 2.5 million here have no electricity. in the air and in the water, the frantic search for survivors

continues. in this dramatic new video watch as a rescue team pulls two small children from their destroyed home reuniting them with their family on safe ground. for the last 24 hours, helicopters have been circling the epicenter of destruction near sendai carrying survivors to safety. but for the thousands of people left without homes, water or electricity, the desperation is starting to set in. >> my apartment is unlivable right now. the foundation is all cracked, plaster everywhere. everything just broken. everything that's breakable is broken. >> reporter: have you ever seen anything like this? we discovered the growing need as we circled that evacuation zone that's now been widened around those troubled nuclear reactors. we discovered homes flattened even in rural japan dozens of miles inland. and the lines are everywhere. this massive line just for water. and an 11-year-old girl who told us she's had no water for more than two days filling up several jugs for her family. do you have any lights? do you have any power?

she tells us her family has had no electricity. and like so many people here, they're now running short on food. at this convenience store the lights are out but the aisles have begun to empty. this mother said she came out only because she had to. she was running out of food but she was also very nervous to leave her home. are you nervous about the nuclear reactors? yes, she is very concerned, she told us, saying she doesn't know what to do. telling us she's simply been following directions on television not to go outside. and that young mother, like so many parents i spoke with, concerned about the safety of their children, particularly with the scares involving the nuclear reactors. they say they're trying to follow the rules and the lessons being said on state television here, which is to stay home and keep the windows sealed. but at the same time she simply said i was running out of food. i had to go to the store and that's why we ran into her. heading out, long lines everywhere for gas, water and food here. dan, bianna, back to you. >> all right, david, and we know

you'll have much more tonight on "world news" from japan. meantime, the state department says it has received hundreds of inquiries about americans who are either missing or unaccounted for in japan, and our linsey davis joins us now with americans' frantic search for missing loved ones. >> good morning. many american families are turning to their local japanese-american societies, the red cross and also the state department for help, but the internet is also proving extremely useful. this indianapolis sushi chef is like many japanese-americans who haven't been able to reach loved ones at home. >> my father and mother and then my brother and sister. >> reporter: in portland, julia heasley hasn't heard from her daughter kate since an e-mail last week. >> it's not easy. it's really hard. you know, just waiting and not having anything you can do. >> reporter: but this disaster has a new tool in search and recovery, social media and the internet. >> i have my lifelines here. i've got my bible, my phone, and my computer. >> reporter: social networking

sites like facebook, twitter and google's people finder have been critical for those looking for the lost. in seattle the strumlauser was desperately trying to find their 27-year-old son, aaron, who was working in sendai, when the quake struck. >> we have no way of reaching him. communications, the infrastructure there is down. it's very worrisome. we're obviously -- >> it's terrifying, the pictures. >> reporter: but just hours after this interview, facebook came to the rescue. someone on the site confirmed that aaron was alive. laura westindorf has been searching for her brother, his wife and daughter. >> hoping that maybe they're all at her school. >> reporter: last night she finally heard from them the old-fashioned way, by phone. >> hi. how are you? and i'm like, oh, my god, you're alive. you know, it was very, very exciting and very happy. >> we finally made contact when everything was down and it was sort of chaos. we were definitely dependent on the older technologies, absolutely. it was a radio with batteries

was a wonderful, wonderful thing to have and then as time passed then, it seemed like we were climbing a technological ladder a step at a time. >> reporter: and in chicago last night, the reunions were face to face. >> i think she's better now. >> i'm happy that he's home. >> reporter: our story kept changing last night largely for the better. just within the last 24 hours, there were many stories of people getting in contact with their relatives for the first time since the quake. those e-mails and phone calls obviously bring a sense of relief, but also some really difficult stories about the lack of water, unsafe conditions and the difficulty still communicating. >> nice to see those reunions but also really wrenching to see the mother with her lifelines, the bible, the phone, the computer. >> and so helpless. >> yeah, nothing she can do. >> thousands of miles away. linsey, thank you. let's get the rest of the morning's headlines now once again with ron claiborne. >> i'm back, good morning again, dan, bianna, linsey, everyone. libyan government forces loyal to moammar gadhafi have reclaimed more towns that had been taken by rebels. meanwhile, in cairo the arab

league asked the u.n. security council to impose a no-fly zone to protect the rebels over libya. at least 17 people were injured in an apartment building fire here in new york city. three are in critical condition and two others are in serious condition. meanwhile, in haiti, hip-hop star wyclef jean performed on stage for a presidential candidate ahead of the march 20th elections there. the winner of the election will have to deal with the aftermath of the devastating earthquake that killed 250,000 people. finally, minnesota congresswoman michelle bachman spoke at a rally in new hampshire on saturday, and she flubbed some important history and geography. bachmann, who is a possible republican presidential contender in 2012, said "you're the state where the shot was heard around the world in lexington and concord," and as dan knows, the two towns were actually in neighboring massachusetts. >> they said, no, we're not. >> exactly. time now for the weather and stephanie roberts from our tampa, florida, affiliate, wfts, stephanie? >> good morning. we have our geography down this morning. we're going to start in the

northeast. we have a pretty dry weekend. unfortunately, flooding concerns continue. the passaic river in wayne, new jersey, has crested. but flooding expected to be a problem there for the next couple of days. now, the good news is it will be dry across the northeast today with some wind di and warm conditions near the coastline. now the flooding concerns have brought us to the midwest due mostly to snow melt with the warmer temperatures. we're watching a storm system in the northwest part of the country where there will be watches and warnings for wind and also interior mountain snows. some heavy rains from seattle down north to san francisco. that's what's happening across the country. >> this weather report has been brought to you by the united states postal service. bianna and dan? >> stephanie, thank you. and coming up on "good morning america," the question that many americans are asking,

what if it happened here? how a massive disaster like the one in japan would impact the u.s. >> the question is, are we ready? also this morning, we've got a special edition of "your week in three words." stick with us here on "gma" on this sunday morning. your advertising mail campaign is paying off! business is good! it must be if you're doing all that overnight shipping. that must cost a fortune. it sure does. well, if it doesn't have to get there overnight, you can save a lot with priority mail flat rate envelopes. one flat rate to any state, just $4.95. that's cool and all... but it ain't my money. i seriously do not care... so, you don't care what anyone says, you want to save this company money! that's exactly what i was saying. hmmm... priority mail flat rate envelopes, just $4.95 only from the postal service. a simpler way to ship. you're unpacking already? yeah. help me find some mugs? ♪ the best part of wakin' up... ♪ [ beep ] hey. [ giggles ]ok. ♪ ...is folgers in your cup

but sometimes i wonder... what's left behind? [ female announcer ] introducing purifying facial cleanser from neutrogena® naturals. developed with dermatologists... it's clinically proven to remove 99% of dirt and toxins and purify pores. and with natural willowbark it contains no dyes, parabens or harsh sulfates. dirt and toxins do a vanishing act and my skin feels pure and healthy. [ female announcer ] new purifying facial cleanser from the new line of neutrogena naturals. a million dollar makeover. we're down to eight contestants, now we need you to help us choose the winner on facebook. you could even win a 500 dollar macy's gift card. macy's million dollar makeover. vote now at facebook.com/macys.

breakfast for lunch. breakfast for dinner. with three new breakfast lovers dishes, who needs a break from breakfast? denny's. america's diner is always open.

well, the massive earthquake that rocked japan was the largest ever to hit that country and number five on the list of most powerful quakes in the past century. the biggest one ever in the u.s. hit prince william sound in alaska in 1964 and measured 9.2. so what do these numbers really mean? ron is here with an explanation. good morning, ron. >> good morning again, bianna. well, the quake that hit japan was an 8.9 magnitude. to give you a sense of what that means, every one number jump in magnitude is equal to the ground motion as recorded on a seismograph going up ten times. and it releases 32 times as much energy. the earthquake that caused so much destruction in haiti last year was a 7.0. that means that the quake in japan gave off 60 times the force of the one that devastated haiti. now, all of this raises the question, what would a major

quake do if it happened here in the u.s.? >> a portion as you can see of the upper level has collapsed onto the lower level. >> reporter: in 1989 san francisco was rocked by a 6.9 earthquake. [ sirens ] in 1994 it was l.a.'s turn, a 6.7 that caused billions in damage and killed 61, but these were minor compared to friday's powerful 8.9 earthquake off the coast of japan. >> in california from what we understand about the faults that are active, probably the biggest earthquakes we'd expect are about a magnitude 8.0. >> reporter: in 2008 the u.s. geological service did a large-scale drill imagining what would happen if a 7.8 quake struck southern california. in this video simulation, los angeles is roiled as if it were sitting on top of a turbulent sea. newer buildings built to california's tough earthquake code would stand. older, unreinforced structures would not.

>> after the first waves that are coming right at you, you're starting to see waves bouncing back and forth in the low-lying area in the los angeles basin. >> we're talking about a lot of damage and destruction here, aren't we? >> that's right. >> reporter: the expert's conclusion, at least 1,800 dead and massive destruction. >> 63,000 people will be injured and $213 billion in damage will occur. >> reporter: california is home to four nuclear power plants. one of which, san onofre, is right near the ocean in san diego where over 1 million people live. the japanese earthquake shows how vulnerable the pacific coast of the u.s. is to a tsunami. abc's clayton sandell is in crescent city, california, where it inflicted the most damage. >> the waves came ashore here basically destroying the marina. experts tell us if the same 8.9 quake happened off our shores, it could drive a 20 to 30-foot wall of water as far as two miles inland.

>> reporter: and it's not just the west coast where a damaging earthquake could strike. the entire country is crisscrossed with faults, though none as potentially dangerous as in california. the new madrid fault runs from st. louis to memphis, and the ramapo fault runs through pennsylvania, new york, and new jersey, one tentacle passing right through manhattan. even a moderate ramapo earthquake could cause major damage to an area that is home to millions. earthquake experts say that the strongest magnitude quake that could hit the mainland of the u.s. is around 8, but there are geological conditions in alaska and off the coast of washington and oregon where a 9 or higher could occur and as bianna was saying has occurred in the past, and, of course, that would be even stronger than the one that wreaked so much havoc in japan. >> you hear how the infrastructure is so much better prepared in japan than in the u.s. for an earthquake. i was just there three months ago, and there was close to a 7.0 earthquake that we didn't even feel, so that gives you the magnitude of how big this one given the destruction that we saw there. >> it was a 7.0 that did so much

damage in haiti, and 60 times stronger in japan and so much less damage in tokyo. but it tells you how building codes can make a huge difference. >> and the california code is very stringent, not quite up to japanese standards but stringent for new buildings. >> fascinating, ron. we'll be back in a minute with a special edition of "your week in three words" with your messages for the people of japan. stay with us. the sensitivity was caused by my brushing too hard.

i went to the dentist. the dentist thinks that i brush my teeth a little too hard. when he was poking around, he found the spots, and he said, "are those spots sensitive?" yep, you found them. he recommended that i use sensodyne, and he just said to make sure i use it as the only toothpaste, however many times a day, just make sure it's always with sensodyne. i noticed that it was working when i was drinking cold things and i wasn't even thinking about it. the sensodyne definitely helped in those spots. i never thought a toothpaste could fix that problem.

i never thought a toothpaste a tool where people can enter the terms of the refinance offer they got from their mortgage guy, and know instantly if they're getting bamboozled. and i will start after lunch...tomorrow. don't just think about it. introducing lendingtree's free "look before you lock" tool. enter the terms of your existing loan offer to instantly find out how it compares to other offers, areas you may be overpaying, and even negotiation points to help you get a better deal. only at lendingtree.

this gives you a sense of how much interest there is in the story. yesterday at noon we put out a call on facebook and twitter for people to send us messages for people in japan for our segment "your week in three words" and got hundreds of them and dozens of videos and put them together overnight. the music in the background is adele's "set fire to the rain" and here it is, "your week in three words." ♪ i let it fall my heart and as it fell you rose to claim it ♪ ♪ it was dark and i was over it will you kissed my lips and you saved me ♪ ♪ my hands they were strong but my knees were far too weak ♪ ♪ to stand in your arms without falling to you are feet ♪ ♪ but there's a sigh side to you

that i never knew never knew ♪ ♪ all the things you'd say they were never true never true ♪ ♪ and the games you'd play you would always win always win ♪ ♪ but i set fire to the rain ♪ watched it pour as i touched your face ♪ ♪ well it burned while i cried cause i heard it creaming out your name your name the last time ♪ >> just a glimpse of the thousands sending their thoughts and prayers to japan. >> that was a pretty incredible video. you can always send us your three words. go to abcnews.com/gma to upload your video, and we're going to

be right back after a quick break. what makes even the lightest touch linger? new smooth sensation from nivea. the light lotion with the breakthrough skin care technology. 24-hour-plus hydra iq. it works with your skin's hydration system to keep skin smooth. all day, all night. ♪ smooth sensation and the essentials collection. now with hydra iq. only from nivea. touch and be touched.

♪ [ female announcer ] mini, meet berries. introducing new kellogg's frosted mini-wheats with a touch of fruit in the middle. helloooooo fruit in the middle. with a touch of fruit in the middle. heaven comes to earth. rich, creamy, thick dannon greek, the most delicious yogurt heaven on earth! discover dannon greek [bell tolls] - to best serve your customers, you have to know them. personally. only a local agent can do that. [click, motor hums] - doug pierce. lives in tornado alley. - hobby? - collects stamps. - excellent. - annette thompson. small business owner. hates cantaloupe. - good. - the lee family: twins. with another on the way. - mazel tov. - that's meatloaf. - hmm. [click] that's still meatloaf. - very good. moving on. - we are insurance. - ♪ we are farmers ♪ bum di bum bum bum bum bum ♪

so i live claritin clear. only claritin is proven to keep me as alert and focused as someone without allergies. i get relief from my worst symptoms without drowsiness. live claritin clear.

and as always we want to thank you for watching abc news for all the latest on the disaster. we're always online at abcnews.com. david muir will anchor

"world news" from japan and christiane amanpour is in tokyo for "this week with christiane amanpour." and tomorrow night diane sawyer will anchor the show from there as well. thanks again for joining us. have a great rest of your weekend.

switching to progressive could mean hundreds more in your wallet year after year. feed me! saving you money -- now, that's progressive. call or click today.